The article provides an in-depth exploration of best practices for implementing logging in .NET Core 3.1 applications, emphasizing the significance of effective logging for monitoring production applications. It outlines the middleware approach used in .NET Core, which integrates logging libraries, both Microsoft-supported and third-party, via the NuGet package manager. The piece guides readers through setting up and configuring logging within a .NET Core application, including injecting logger dependencies into classes, utilizing different logging levels, and configuring output destinations like JSON files using third-party libraries such as Serilog. It also covers advanced techniques like middleware for logging exceptions and HTTP requests, Aspect-Oriented Programming, and the Sidecar process to enhance logging efficiency and maintain code clarity. Additionally, the article addresses performance considerations in high-load scenarios, suggesting methods to optimize log processing without compromising the application's performance.